scholarly journals A standardised method of marking male mosquitoes with fluorescent dust

2020 ◽  
Author(s):  
Nicole J Culbert ◽  
Maria Kaiser ◽  
Nelius Venter ◽  
Marc J. B. Vreysen ◽  
Jeremie R. L. Gilles ◽  
...  

Abstract Background: Prior to a major release campaign of sterile insects, including the sterile insect technique, male mosquitoes must be marked and released (small scale) to determine key parameters including wild population abundance, dispersal and survival.Marking insects has been routinely carried out for over 100 years, however, there is no gold standard regarding the marking of specific disease-transmitting mosquitoes including Anopheles arabiensis, Aedes aegypti and Aedes albopictus . The research presented offersa novel dusting technique and optimal dust colour and quantities, suitable for small-scale releases, such as mark-release-recapture studies. Methods: We sought to establish a suitable dust colour and quantity for batches of 100 male An. arabiensis , that was visible both by eye and under UV light, long lasting and did not negatively impact longevity. A set of lower dust weights were selected to conduct longevity experiments with both Ae. aegypti and Ae. albopictus to underpin the optimal dust weight. A further study assessed the potential of marked male An. arabiensis to transfer their mark to undusted males and females. Results: The longevity of male An. arabiensis marked with various dust colours was not significantly reduced when compared to unmarked controls. Furthermore, the chosen dust quantity (5 mg) did not negatively impact longevity ( P = 0.717) and provided a long-lasting mark. Dust transfer was found to occur from marked An. arabiensis males to unmarked males and females when left in close proximity. However, this was only noticeable when examining individuals under a stereomicroscope and thus deemed negligible. Overall, male Ae. aegypti and Ae. albopictus displayed a greater sensitivity to dusting. Only the lowest dust weight (0.5 mg) did not significantly reduce longevity ( P = 0.888) in Ae. aegypti, whilst the lowest two dust weights (0.5 and 0.75 mg) had no significant impact on longevity ( P = 0.951 and 0.166) respectively in Ae. albopictus . Conclusion: We have devised a fast, inexpensive and simple marking method and provided recommended dust quantities for several major species of disease-causing mosquitoes. The novel technique provides an evenly distributed, long-lasting mark which is non-detrimental. Our results will be useful for future MRR studies, prior to a major release campaign.

2019 ◽  
Author(s):  
Nicole J Culbert ◽  
Maria Kaiser ◽  
Nelius Venter ◽  
Marc J. B. Vreysen ◽  
Jeremie R. L. Gilles ◽  
...  

Abstract Background Prior to a major release campaign of sterile insects, including the sterile insect technique, male mosquitoes must be marked and released (small scale) to determine key parameters including wild population abundance, dispersal and survival. Marking insects has been routinely carried out for over 100 years, however, there is no gold standard regarding the marking of specific disease-transmitting mosquitoes including Anopheles arabiensis, Aedes aegypti and Aedes albopictus . The research presented offers a novel dusting technique and optimal dust colour and quantities, suitable for small-scale releases, such as mark-release-recapture studies.Methods We sought to establish a suitable dust colour and quantity for batches of 100 male An. arabiensis , that was visible both by eye and under UV light, long lasting and did not negatively impact longevity. A set of lower dust weights were selected to conduct longevity experiments with both Ae. aegypti and Ae. albopictus to underpin the optimal dust weight. A further study assessed the potential of marked male An. arabiensis to transfer their mark to undusted males and females.Results The longevity of male An. arabiensis marked with various dust colours was not significantly reduced when compared to unmarked controls. Furthermore, the chosen dust quantity (5 mg) did not negatively impact longevity ( P = 0.717) and provided a long-lasting mark. Dust transfer was found to occur from marked An. arabiensis males to unmarked males and females when left in close proximity. However, this was only noticeable when examining individuals under a stereomicroscope and thus deemed negligible. Overall, male Ae. aegypti and Ae. albopictus displayed a greater sensitivity to dusting. Only the lowest dust weight (0.5 mg) did not significantly reduce longevity ( P = 0.888) in Ae. aegypti, whilst the lowest two dust weights (0.5 and 0.75 mg) had no significant impact on longevity ( P = 0.951 and 0.166) respectively in Ae. albopictus .Conclusion We have devised a fast, inexpensive and simple marking method and provided recommended dust quantities for several major species of disease-causing mosquitoes. The novel technique provides an evenly distributed, long-lasting mark which is non-detrimental. Our results will be useful for future MRR studies, prior to a major release campaign.


1995 ◽  
Vol 50 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Andreas Karst ◽  
Burkhardt Broschk ◽  
Joseph Grobe ◽  
Duc Le Van

Reaction of the cyclotetraphosphane (PCF3)4 or of a mixture of (PCF3)4 and (PCF3)5 with 2,3-dimethyl-1,3-butadiene or isoprene at 25 °C leads to the [4 + 2]-cycloadducts of bis(trifluoromethyl) diphosphene and the phospholene derivatives 2a and 2b, respectively, in the molar ratio diphosphinine/phospholene = 1/2. The analogous reactions of the cycloarsanes (AsCF3)4,5 give the Diels/Alder compounds 4 and 5 of bis(trifluoromethyl)diarsene in 90% yield without arsolene formation. Cyclopentadiene, 1,3-cyclohexadiene and cis or trans piperylene do not react with (AsCF3)4,5, up to temperatures of 60 °C. However, the corresponding [4 + 2]-cycloadducts 6 - 8 are produced by irradiation of the reaction mixture with UV light. The novel phospholenes 2a and 2b as well as the diarsinines 4 - 8 have been characterized by spectroscopic data (MS, NMR, IR). 2a was coordinated as a phosphane ligand to the pentacarbonylchromium fragment by reaction with the photochemically generated complex Cr(CO)5 · THF to afford the new compound (3).


2009 ◽  
Vol 1171 ◽  
Author(s):  
Marco Bonato ◽  
Kristin Vala Ragnarsdottir ◽  
Geoffrey C. Allen

AbstractTiO2 anatase nanotubes synthesised via anodic oxidation were used as adsorbent for the uptake of U and Pb from aqueous solution and the photoremoval of As(III). An X-ray photoelectron spectroscopy study of the sorbent medium surface revealed a high adsorption of U and Pb at pH 8. The adsorption of the uranyl ion was enhanced in an anoxy (N2) atmosphere, because this prevents the formation of very stable carbonyl complexes. As(III) was adsorbed on TiO2 but in the presence of O2 and UV light was oxidized to As(V). XPS analysis revealed that in the pH range 3-9 As(V) was always the major species detected at the surface of the titania photocatalyst.


Antiquity ◽  
1954 ◽  
Vol 28 (110) ◽  
pp. 91-98 ◽  
Author(s):  
H. S. Gracie

The barren hill-tops of Malta are scored in many places by ancient ruts cut deeply into the rock. They can be seen also on the slopes and on the lower plains, but less frequently because these areas are normally under agricultural soil. They always occur in pairs from 52 to 58 inches apart and were quite clearly used by vehicles. They have been discussed in print for 300 years but no agreement has been reached on how, when or why they were made or what vehicles used them. In fact, there are as many theories as there are authors. Of these writers only Captain E. G. Fenton and Professor Sir T. Zammit appear to have done any serious field work, and none has published a map. The present writer, therefore, decided to attempt the laborious task of plotting them, making such other observations and measurements as he could. Zammit, in the paper cited, reproduced some excellent photographs from both the ground and the air, to which the reader is referred.Time did not permit an examination of the whole island and few observations were made in the low-lying south-eastern part. A fairly intensive survey was made of the high ground as far north as the Baida Ridge, which joins the northern shores of Ghain Tuffieha Bay and St. Paul’s Bay. Two portions of the map are reproduced here. Where there are a number of parallel tracks in close proximity they are shown on the map as one on account of the necessarily small scale used. The gaps in the routes are mainly due to cultivated patches, and no attempt has been made to bridge them by conjecture.


2021 ◽  
Author(s):  
Elena Vranchan

The article deals with the peculiarities of the patriarchal noble-peasant life description in the novel “The Life of Arseniev” (1930) by Ivan Bunin, focuses on the use of characteristic Gogol’s images and techniques. Moreover, the comparison of the artistic interpretation ways of the patriarchal past by the writers reveals the Gogol's influence on the position of Bunin as the author, which is presented in the novel in different ways: from the point of view of an observer narrator who topographically accurately depicts the reality and life of the family estate, and from the point of view of an emigrant, focused on memories of the past, conveying an emotional sense of the connection between generations. In general, Bunin continues to develop the theme of the collision of immobile patriarchy with the quick movement of time that destroys the old serfdom, so his novel is imbued with nostalgia for the small-scale world going into the past. In Bunin's nostalgia, there are echoes of Gogol's sorrow about the doomed old world life.


2019 ◽  
Author(s):  
Lace Padilla

The Morris water maze is a task adapted from the animal spatial cognition literature and has been studied in the context of sex differences in humans, particularly because of the standard design, which manipulates proximal (close) and distal (far) cues. However, there are mixed findings with respect to the interaction of cues and sex differences in virtual Morris water maze tasks, which may be attributed to variations in the scale of the space and previously unmeasured individual differences. We explore the question of scale and context by presenting participants with an outdoor virtual Morris water maze that is four times the size of the mazes previously tested. We also measured lifetime mobility and mental rotation skills. Results of this study suggest that for the small-scale environment, males and females performed similarly when asked to navigate with only proximal cues. However, males outperformed females when only distal cues were visible. In the large-scale environment, males outperformed females in both cue conditions. Additionally, greater mental rotation skills predicted better navigation performance with proximal cues only. Finally, we found that highly mobile females and males perform equally well when navigating with proximal cues.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Fang ◽  
Jie Chen ◽  
Honghua Ruan ◽  
Nan Xu ◽  
Ziting Que ◽  
...  

The earthworm species Metaphire vulgaris (a member of the Clitellata class) is widely distributed across China, and has important ecological functions and medicinal value. However, investigations into its genetic diversity and differentiation are scarce. Consequently, we evaluated the genetic diversity of five populations of M. vulgaris (GM, HD, NYYZ, QDDY, and QDY) in Yancheng, China via the mitochondrial COI gene and the novel microsatellites developed there. A total of nine haplotypes were obtained by sequencing the mitochondrial COI gene, among which NYYZ and QDDY populations had the greatest number of haplotypes (nh = 5). Further, the nucleotide diversity ranged from 0.00437 to 0.1243. The neighbor-joining trees and the TCS network of haplotypes indicated that earthworm populations within close geographical range were not genetically isolated at these small scale distances. Results of the identification of microsatellite molecular markers revealed that the allele number in 12 microsatellite loci ranged from 4 to 13. The observed heterozygosity ranged from 0.151 to 0.644, whereas the expected heterozygosity ranged from 0.213 to 0.847. The polymorphism data content of most sites was >0.5, which indicated that the designed sites had high polymorphism. Structural analysis results indicated that GM, HD, and NYYZ had similar genetic structures across the five populations. The Nei’s genetic distance between HD and NYYZ populations was the smallest (Ds = 0.0624), whereas that between HD and QDY populations was the largest (Ds = 0.2364). The UPGMA tree showed that HD were initially grouped with NYYZ, followed by GM, and then with QDDY. Furthermore, cross-species amplification tests were conducted for Metaphire guillelmi, which indicated that the presented markers were usable for this species. This study comprised a preliminary study on the genetic diversity of M. vulgaris, which provides basic data for future investigations into this species.


1999 ◽  
Author(s):  
John M. Coggin ◽  
Jeffrey M. K. Chock ◽  
Rakesh K. Kapania ◽  
Eric R. Johnson

Abstract We study the transient response of simply supported composite plates subject to close proximity explosions. Many studies are currently availiable in which the blast load is applied uniformly across the plate; and is described by step, N-pulse, or Friedlander equations. The novel aspect considered here is the case for which the blast pressure is due to a close proximity explosion, and is therefore taken to be both spatially and temporally varying. Two methods for calculating blast pressures are developed for arbitrary blast size and distance. A FORTAN program is described that automates the application of an arbitrary blast load to a generic finite element mesh. Modal superposition and NASTRAN solution procedures are verified for several load types and stacking sequences. Results are obtained within the framework of classical and first order plate theories for a variety of parameters including; stacking sequence, blast size, blast distance, and blast calculation method.


1999 ◽  
Vol 202 (20) ◽  
pp. 2727-2738 ◽  
Author(s):  
M.C. Gopfert ◽  
H. Briegel ◽  
D. Robert

Male mosquitoes are attracted by the flight sounds of conspecific females. In males only, the antennal flagellum bears a large number of long hairs and is therefore said to be plumose. As early as 1855, it was proposed that this remarkable antennal anatomy served as a sound-receiving structure. In the present study, the sound-induced vibrations of the antennal flagellum in male and female Aedes aegypti were compared, and the functional significance of the flagellar hairs for audition was examined. In both males and females, the antennae are resonantly tuned mechanical systems that move as simple forced damped harmonic oscillators when acoustically stimulated. The best frequency of the female antenna is around 230 Hz; that of the male is around 380 Hz, which corresponds approximately to the fundamental frequency of female flight sounds. The antennal hairs of males are resonantly tuned to frequencies between approximately 2600 and 3100 Hz and are therefore stiffly coupled to, and move together with, the flagellar shaft when stimulated at biologically relevant frequencies around 380 Hz. Because of this stiff coupling, forces acting on the hairs can be transmitted to the shaft and thus to the auditory sensory organ at the base of the flagellum, a process that is proposed to improve acoustic sensitivity. Indeed, the mechanical sensitivity of the male antenna not only exceeds the sensitivity of the female antenna but also those of all other arthropod movement receivers studied so far.


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